ECU INFINITI QX56 2010 Factory Service Manual

P0127 IAT SENSOREC-133
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode with CONSULT-III.
4. Start engine.
5. Hold vehicle speed at more than 70 km/h (43 MPH) for 100 consecutive seconds.
6. Check 1st trip DTC.
7. If 1st trip DTC is detected, go to
EC-133, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149149
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-85, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to EC-133, "
Component Inspection".
OK or NG
OK >> GO TO 3.
NG >> Replace mass air flow sensor ( with intake air temperature sensor).
3.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
Refer to EC-435, "
Wiring Diagram - ENGINE CONTROL SYSTEM -".
>> INSPECTION END
Component InspectionINFOID:0000000005149150
INTAKE AIR TEMPERATURE SENSOR
1. Check resistance between intake air temperature sensor termi-
nals 5 and 6 under the following conditions.
2. If NG, replace mass air flow sensor (with intake air temperature sensor).
BBIA0354E
Intake air temperature ° C (°F)] Resistance (k Ω)
25 (77) 1.800 - 2.200
BBIA0355E
Revision: April 20092010 QX56

P0128 THERMOSTAT FUNCTIONEC-135
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
P0128 THERMOSTAT FUNCTION
On Board Diagnosis LogicINFOID:0000000005149151
NOTE:
If DTC P0128 is displayed with DTC P0300, P0301,
P0302, P0303, P0304, P0305, P0306, P0307 or P0308,
first perform the trouble diag nosis for DTC P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307,
P0308. Refer to EC-192, "
DTC Confirmation Procedure".
Engine coolant temperature has not risen enough to open the thermostat even though the engine has run long
enough.
This is due to a leak in the seal or the thermostat stuck open.
DTC Confirmation ProcedureINFOID:0000000005167702
WITH CONSULT-III
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
• For best results, perform at ambient temperature of –10 °C (14° F) or higher.
• For best results, perform at engine coolant temperature of –10 °C (14° F) to 56 °C (133° F).
• Before performing the following pro cedure, do not fill with the fuel.
1. Turn A/C switch OFF.
2. Turn blower fan switch OFF.
3. Turn ignition switch ON.
4. Select “COOLAN TEMP/S” in “DAT A MONITOR” mode with CONSULT-III.
5. Check the indication of “COOLAN TEMP/S”. If it is below 56 °C (133 °F), go to following step.
If it is above 56 °C (133° F), cool down the engine to less than 56° C (133°F). Then go to next steps.
6. Start engine.
7. Drive vehicle for 10 consecutive minutes under the following conditions.
If “COOLAN TEMP/S” increases to more than 75° C (167°F) within 10 minutes, turn ignition switch
OFF because the test result will be OK.
8. Check 1st trip DTC.
9. If 1st trip DTC is detected, go to EC-135, "
DTC Confirmation Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000005149153
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-136, "
Component Inspection".
OK or NG
OK >> GO TO 2.
NG >> Replace engine coolant temperature sensor.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0128
0128 Thermostat function The engine coolant temperature does not
reach to specified temperature even though
the engine has run long enough. •Thermostat
• Leakage from sealing portion of thermostat
• Engine coolant temperature sensor
VHCL SPEED SE More than 56 km/h (35 MPH)
Revision: April 20092010 QX56

EC-142
< COMPONENT DIAGNOSIS >[VK56DE]
P0131, P0151 A/F SENSOR 1
6. Maintain the following conditions for about 20 consecutive seconds.
NOTE:
•Keep the accelerator pedal as steady as possible during the cruising.
• If this procedure is not completed within 1 minute af ter restarting engine at step 4, return to step
4.
7. Check 1st trip DTC.
8. If 1st trip DTC is displayed, go to EC-142, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000005149163
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-85, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect A/F sensor 1 harness connector.
2. Turn ignition switch ON.
ENG SPEED 1,000 - 3,200 rpm
VHCL SPEED SE More than 40 km/h (25 MPH)
B/FUEL SCHDL 1.5 - 9.0 msec
Gear position Suitable position
BBIA0354E
BBIA0376E
Revision: April 20092010 QX56

EC-146
< COMPONENT DIAGNOSIS >[VK56DE]
P0132, P0152 A/F SENSOR 1
6. Maintain the following conditions for about 20 consecutive seconds.
NOTE:
•Keep the accelerator pedal as steady as possible during the cruising.
• If this procedure is not completed within 1 minute af ter restarting engine at step 4, return to step
4.
7. Check 1st trip DTC.
8. If 1st trip DTC is displayed, go to EC-146, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000005149167
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-85, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect A/F sensor 1 harness connector.
2. Turn ignition switch ON.
ENG SPEED 1,000 - 3,200 rpm
VHCL SPEED SE More than 40 km/h (25 MPH)
B/FUEL SCHDL 1.5 - 9.0 msec
Gear position Suitable position
BBIA0354E
BBIA0376E
Revision: April 20092010 QX56

P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
EC-173
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Start engine.
c. Maintain the following conditions for at least 10 consecutive minutes.
Hold the accelerator pedal as steady as possible.
CAUTION:
Always drive vehicle at a safe speed.
d. Check 1st trip DTC.
e. If 1st trip DTC is detected, go to EC-173, "
Diagnosis Procedure".
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Disconnect mass air flow sensor harness connector.
6. Restart engine and let it idle for at least 5 seconds.
7. Stop engine and reconnect mass air flow sensor harness con-
nector.
8. Select Service $03 with GST. Make sure DTC P0102 is detected.
9. Select Service $04 with GST and erase the DTC P0102.
10. Start engine. If it is difficult to start engine, the fuel injection system has a mal-
function.
Performing the following procedure is advised.
a. Crank engine while depressing accelerator pedal. NOTE:
When depressing accelerator pedal three-fourths (3/4) or more, the control system does not start the
engine. Do not depress accelerator pedal too much.
b. If engine starts, go to EC-173, "
Diagnosis Procedure".
If engine does not start, check exhaust and intake air leakage visually.
11. Keep engine at idle for at least 5 minutes.
12. Check 1st trip DTC.
13. The 1st trip DTC P0171 or P0174 should be detected at this stage, if a malfunction exists. If so, go to EC-
173, "Diagnosis Procedure".
NOTE:
If 1st trip DTC is not detected during above proc edure, performing the following procedure is advised.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Start engine.
c. Maintain the following conditions for at least 10 consecutive minutes. Hold the accelerator pedal as steady as possible.
CAUTION:
Always drive vehicle at a safe speed.
d. Check 1st trip DTC.
e. If 1st trip DTC is detected, go to EC-173, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149192
1.CHECK EXHAUST GAS LEAK
VHCL SPEED SE50 - 120 km/h (31 - 75 MPH)
VHCL SPEED SE50 - 120 km/h (31 - 75 MPH)
BBIA0368E
Revision: April 20092010 QX56

EC-178
< COMPONENT DIAGNOSIS >[VK56DE]
P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
c. Maintain the following conditions for at least 10 consecutive minutes.
Hold the accelerator pedal as steady as possible.
CAUTION:
Always drive vehicle at a safe speed.
d. Check 1st trip DTC.
e. If 1st trip DTC is detected, go to EC-173, "
Diagnosis Procedure".
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Disconnect mass air flow sensor harness connector.
6. Restart engine and let it idle for at least 5 seconds.
7. Stop engine and reconnect mass air flow sensor harness con-
nector.
8. Select Service $03 with GST. Make sure DTC P0102 is detected.
9. Select Service $04 with GST and erase the DTC P0102.
10. Start engine. If it is difficult to start engine, the fuel injection system has a mal-
function.
Performing the following procedure is advised.
a. Crank engine while depressing accelerator pedal. NOTE:
When depressing accelerator pedal three-fourths (3/4) or more, the control system does not start the
engine. Do not depress accelerator pedal too much.
b. If engine starts, go to EC-178, "
Diagnosis Procedure".
If engine does not start, check exhaus t and intake air leakage visually.
11. Keep engine at idle for at least 5 minutes.
12. Check 1st trip DTC.
13. The 1st trip DTC P0172 or P0175 should be detected at this stage, if a malfunction exists. If so, go to EC-
173, "Diagnosis Procedure".
NOTE:
If 1st trip DTC is not detected during above proc edure, performing the following procedure is advised.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Start engine.
c. Maintain the following conditions for at least 10 consecutive minutes. Hold the accelerator pedal as steady as possible.
CAUTION:
Always drive vehicle at a safe speed.
d. Check 1st trip DTC.
e. If 1st trip DTC is detected, go to EC-173, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149195
1.CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
VHCL SPEED SE 50 - 120 km/h (31 - 75 MPH)
VHCL SPEED SE50 - 120 km/h (31 - 75 MPH)
BBIA0368E
Revision: April 20092010 QX56

P0420, P0430 THREE WAY CATALYST FUNCTIONEC-209
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
P0420, P0430 THREE WAY CATALYST FUNCTION
On Board Diagnosis LogicINFOID:0000000005149229
The ECM monitors the switching
frequency ratio of air fuel sensor
(A/F) sensor 1 and heated oxygen sensor 2.
A three way catalyst (manifold) with high oxygen storage capacity
will indicate a low switching frequency of heated oxygen sensor 2.
As oxygen storage capacity decreases, the heated oxygen sensor 2
switching frequency will increase.
When the frequency ratio of air fuel ratio (A/F) sensor 1 and heated
oxygen sensor 2 approaches a specified limit value, the three way
catalyst (manifold) malfunction is diagnosed.
DTC Confirmation ProcedureINFOID:0000000005149230
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
WITH CONSULT-III
TESTING CONDITION:
Do not hold engine speed for more than the specified minutes below.
1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-III.
2. Start engine and warm it up to the normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. Make sure that “COOLAN TEMP/S” indicates more than 70 °C (158° F).
If not, warm up engine and go to next step when “COOLAN TEMP/S” indication reaches to 70°C (158° F).
7. Open engine hood.
8. Select “DTC & SRT CONFIRMATION” then “SRT WORK SUPPORT” mode with CONSULT-III.
9. Rev engine up to 2,000 to 3,000 rpm and hold it for 3 consecutive minutes then release the accelerator pedal completely.
If “INCMP” of “CATALYST” changed to “CMPLT”, go to step 12.
10. Wait 5 seconds at idle.
11. Rev engine up to 2,000 to 3,000 rpm and maintain it unt il “INCMP” of “CATALYST” changes to “CMPLT” (It
will take approximately 5 minutes).
If not “CMPLT”, stop engine and cool it down to less than 70 °C (158° F) and then retest from step 1.
12. Select “SELF-DIAG RESU LTS” mode with CONSULT-III.
PBIB2055E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0420
0420
(Bank 1) Catalyst system efficien-
cy below threshold • Three way catalyst (manifold) does not oper-
ate properly.
• Three way catalyst (manifold) does not have enough oxygen storage capacity. • Three way catalyst (manifold)
• Exhaust tube
• Intake air leaks
• Fuel injector
• Fuel injector leaks
• Spark plug
• Improper ignition timing
P0430
0430
(Bank 2)
Revision: April 20092010 QX56

EC-220
< COMPONENT DIAGNOSIS >[VK56DE]
P0442 EVAP CONTROL SYSTEM
OK or NG
OK >> GO TO 3.
NG >> 1. Open fuel filler cap, then clean cap and
fuel filler neck threads using air blower.
2. Retighten until ratcheting sound is heard.
3.CHECK FUEL FILLER CAP FUNCTION
Check for air releasing sound while opening the fuel filler cap.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4.CHECK FUEL TANK VACUUM RELIEF VALVE
Refer to EC-268, "
Component Inspection".
OK or NG
OK >> GO TO 5.
NG >> Replace fuel filler cap with a genuine one.
5.INSTALL THE PRESSURE PUMP
To locate the EVAP leak, install EVAP service port adapter (commer-
cial service tool) and pressure pump to EVAP service port securely.
NOTE:
Improper installation of the EV AP service port adapter to the
EVAP service port may cause leaking.
With CONSULT-III>>GO TO 6.
Without CONSULT-III>>GO TO 7.
6.CHECK FOR EVAP LEAK
With CONSULT-III
1. Turn ignition switch ON.
2. Select “EVAP SYSTEM CLOSE” of “WORK SUPPORT” mode with CONSULT-III.
3. Touch “START” and apply pressure into the EVAP line until the pressure indicator reaches the middle of the bar graph.
CAUTION:
• Never use compressed air or a high pressure pump.
• Do not exceed 4.12 kPa (0.042 kg/cm
2, 0.6 psi) of pressure in the system.
BBIA0366E
SEF916U
Revision: April 20092010 QX56

P0455 EVAP CONTROL SYSTEMEC-255
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
•
Make sure that EVAP hoses are connected to EVAP canister purge volume control solenoid valve
properly.
• If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
• Perform “DTC WORK SUPPORT” when the fuel level is between 1/4 and 3/4 full, and vehicle is placed
on flat level surface.
• Open engine hood before conducting the following procedures.
WITH CONSULT-III
1. Tighten fuel filler cap securely until ratcheting sound is heard.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-III.
5. Make sure that the following conditions are met.
COOLAN TEMP/S: 0 - 70 °C (32 - 158° F)
INT/A TEMP SE: 0 - 60 °C (32 - 140° F)
6. Select “EVP SML LEAK P0442/P1442” of “EVAPO RATIVE SYSTEM” in “DTC WORK SUPPORT” mode
with CONSULT-III.
Follow the instruction displayed.
NOTE:
If the engine speed cannot be maintained within the range displayed on the CONSULT-III screen, go to
EC-13, "
Basic Inspection".
7. Make sure that “OK” is displayed. If “NG” is displayed, select “SELF-DIAG R ESULTS” mode and make sure that “EVAP GROSS LEAK
[P0455]” is displayed. If it is displayed, refer to EC-255, "
Diagnosis Procedure".
If P0442 is displayed, perform Diagnostic Procedure for DTC P0442, EC-219, "
Diagnosis Procedure".
WITH GST
NOTE:
Be sure to read the explanation of EC-459, "
DTC Index" before driving vehicle.
1. Start engine.
2. Drive vehicle according to EC-459, "
DTC Index".
3. Stop vehicle.
4. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
5. Select Service $07 with GST. • If P0441 is displayed on the screen, go to EC-214, "
Diagnosis Procedure".
• If P0442 is displayed on the screen, go to EC-219, "
Diagnosis Procedure".
• If P0455 is displayed on the screen, go to EC-255, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149279
1.CHECK FUEL FILLER CAP DESIGN
1. Turn ignition switch OFF.
Revision: April 20092010 QX56

P0455 EVAP CONTROL SYSTEMEC-257
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
To locate the EVAP leak, install EVAP service port adapter and pres-
sure pump to EVAP service port securely.
NOTE:
Improper installation of the EV
AP service port adapter to the
EVAP service port may cause leaking.
With CONSULT-III>>GO TO 9.
Without CONSULT-III>>GO TO 10.
9.CHECK FOR EVAP LEAK
With CONSULT-II I
1. Turn ignition switch ON.
2. Select “EVAP SYSTEM CLOSE” of “WORK SUPPORT” mode with CONSULT-III.
3. Touch “START” and apply pressure into the EVAP line until the pressure indicator reaches the middle of the bar graph.
CAUTION:
• Do not use compressed air or a high pressure pump.
• Do not exceed 4.12 kPa (0.042 kg/cm
2, 0.6 psi) of pressure in the system.
4. Using EVAP leak detector, locate the EVAP leak. For the leak detector, refer to the instruction manual for more details.
Refer to EC-37, "
Description".
OK or NG
OK >> GO TO 11.
NG >> Repair or replace.
10.CHECK FOR EVAP LEAK
Without CONSULT-III
1. Turn ignition switch OFF.
BBIA0366E
SEF916U
SEF200U
Revision: April 20092010 QX56